Various Sounds from Strowger Equipment

All tones are produced by a Ring Generator; this consists of a
DC motor connected to an AC generator; this gives the basic fixed tones. Gearing adjusts the rotation speed. Various cams, each with different interruptions on their circumferance, then rotate, making and breaking manys contacts, which gives the distinctive cadences. These are all genuine recordings of Strowger equipment. Please note that these sounds are copyright reserved.